Merge tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - A fix for a bug in our page table fragment allocator, where a page
     table page could be freed and reallocated for something else while
     still in use, leading to memory corruption etc. The fix reuses
     pt_mm in struct page (x86 only) for a powerpc only refcount.

   - Fixes to our pkey support. Several are user-visible changes, but
     bring us in to line with x86 behaviour and/or fix outright bugs.
     Thanks to Florian Weimer for reporting many of these.

   - A series to improve the hvc driver & related OPAL console code,
     which have been seen to cause hardlockups at times. The hvc driver
     changes in particular have been in linux-next for ~month.

   - Increase our MAX_PHYSMEM_BITS to 128TB when SPARSEMEM_VMEMMAP=y.

   - Remove Power8 DD1 and Power9 DD1 support, neither chip should be in
     use anywhere other than as a paper weight.

   - An optimised memcmp implementation using Power7-or-later VMX
     instructions

   - Support for barrier_nospec on some NXP CPUs.

   - Support for flushing the count cache on context switch on some IBM
     CPUs (controlled by firmware), as a Spectre v2 mitigation.

   - A series to enhance the information we print on unhandled signals
     to bring it into line with other arches, including showing the
     offending VMA and dumping the instructions around the fault.

  Thanks to: Aaro Koskinen, Akshay Adiga, Alastair D'Silva, Alexey
  Kardashevskiy, Alexey Spirkov, Alistair Popple, Andrew Donnellan,
  Aneesh Kumar K.V, Anju T Sudhakar, Arnd Bergmann, Bartosz Golaszewski,
  Benjamin Herrenschmidt, Bharat Bhushan, Bjoern Noetel, Boqun Feng,
  Breno Leitao, Bryant G. Ly, Camelia Groza, Christophe Leroy, Christoph
  Hellwig, Cyril Bur, Dan Carpenter, Daniel Klamt, Darren Stevens, Dave
  Young, David Gibson, Diana Craciun, Finn Thain, Florian Weimer,
  Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geoff Levand,
  Guenter Roeck, Gustavo Romero, Haren Myneni, Hari Bathini, Joel
  Stanley, Jonathan Neuschäfer, Kees Cook, Madhavan Srinivasan, Mahesh
  Salgaonkar, Markus Elfring, Mathieu Malaterre, Mauro S. M. Rodrigues,
  Michael Hanselmann, Michael Neuling, Michael Schmitz, Mukesh Ojha,
  Murilo Opsfelder Araujo, Nicholas Piggin, Parth Y Shah, Paul
  Mackerras, Paul Menzel, Ram Pai, Randy Dunlap, Rashmica Gupta, Reza
  Arbab, Rodrigo R. Galvao, Russell Currey, Sam Bobroff, Scott Wood,
  Shilpasri G Bhat, Simon Guo, Souptick Joarder, Stan Johnson, Thiago
  Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vasant Hegde, Venkat
  Rao, zhong jiang"

* tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (234 commits)
  powerpc/mm/book3s/radix: Add mapping statistics
  powerpc/uaccess: Enable get_user(u64, *p) on 32-bit
  powerpc/mm/hash: Remove unnecessary do { } while(0) loop
  powerpc/64s: move machine check SLB flushing to mm/slb.c
  powerpc/powernv/idle: Fix build error
  powerpc/mm/tlbflush: update the mmu_gather page size while iterating address range
  powerpc/mm: remove warning about ‘type’ being set
  powerpc/32: Include setup.h header file to fix warnings
  powerpc: Move `path` variable inside DEBUG_PROM
  powerpc/powermac: Make some functions static
  powerpc/powermac: Remove variable x that's never read
  cxl: remove a dead branch
  powerpc/powermac: Add missing include of header pmac.h
  powerpc/kexec: Use common error handling code in setup_new_fdt()
  powerpc/xmon: Add address lookup for percpu symbols
  powerpc/mm: remove huge_pte_offset_and_shift() prototype
  powerpc/lib: Use patch_site to patch copy_32 functions once cache is enabled
  powerpc/pseries: Fix endianness while restoring of r3 in MCE handler.
  powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements
  powerpc/fadump: handle crash memory ranges array index overflow
  ...

1 files changed, 108 insertions, 18 deletions

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 07e8396d472b..986ec476fd5d 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -47,8 +47,10 @@ static struct fadump_mem_struct fdm;
 static const struct fadump_mem_struct *fdm_active;
 
 static DEFINE_MUTEX(fadump_mutex);
-struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES];
+struct fad_crash_memory_ranges *crash_memory_ranges;
+int crash_memory_ranges_size;
 int crash_mem_ranges;
+int max_crash_mem_ranges;
 
 /* Scan the Firmware Assisted dump configuration details. */
 int __init early_init_dt_scan_fw_dump(unsigned long node,
@@ -868,38 +870,107 @@ static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
 	return 0;
 }
 
-static inline void fadump_add_crash_memory(unsigned long long base,
-					unsigned long long end)
+static void free_crash_memory_ranges(void)
+{
+	kfree(crash_memory_ranges);
+	crash_memory_ranges = NULL;
+	crash_memory_ranges_size = 0;
+	max_crash_mem_ranges = 0;
+}
+
+/*
+ * Allocate or reallocate crash memory ranges array in incremental units
+ * of PAGE_SIZE.
+ */
+static int allocate_crash_memory_ranges(void)
 {
+	struct fad_crash_memory_ranges *new_array;
+	u64 new_size;
+
+	new_size = crash_memory_ranges_size + PAGE_SIZE;
+	pr_debug("Allocating %llu bytes of memory for crash memory ranges\n",
+		 new_size);
+
+	new_array = krealloc(crash_memory_ranges, new_size, GFP_KERNEL);
+	if (new_array == NULL) {
+		pr_err("Insufficient memory for setting up crash memory ranges\n");
+		free_crash_memory_ranges();
+		return -ENOMEM;
+	}
+
+	crash_memory_ranges = new_array;
+	crash_memory_ranges_size = new_size;
+	max_crash_mem_ranges = (new_size /
+				sizeof(struct fad_crash_memory_ranges));
+	return 0;
+}
+
+static inline int fadump_add_crash_memory(unsigned long long base,
+					  unsigned long long end)
+{
+	u64  start, size;
+	bool is_adjacent = false;
+
 	if (base == end)
-		return;
+		return 0;
+
+	/*
+	 * Fold adjacent memory ranges to bring down the memory ranges/
+	 * PT_LOAD segments count.
+	 */
+	if (crash_mem_ranges) {
+		start = crash_memory_ranges[crash_mem_ranges - 1].base;
+		size = crash_memory_ranges[crash_mem_ranges - 1].size;
+
+		if ((start + size) == base)
+			is_adjacent = true;
+	}
+	if (!is_adjacent) {
+		/* resize the array on reaching the limit */
+		if (crash_mem_ranges == max_crash_mem_ranges) {
+			int ret;
+
+			ret = allocate_crash_memory_ranges();
+			if (ret)
+				return ret;
+		}
 
+		start = base;
+		crash_memory_ranges[crash_mem_ranges].base = start;
+		crash_mem_ranges++;
+	}
+
+	crash_memory_ranges[crash_mem_ranges - 1].size = (end - start);
 	pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
-		crash_mem_ranges, base, end - 1, (end - base));
-	crash_memory_ranges[crash_mem_ranges].base = base;
-	crash_memory_ranges[crash_mem_ranges].size = end - base;
-	crash_mem_ranges++;
+		(crash_mem_ranges - 1), start, end - 1, (end - start));
+	return 0;
 }
 
-static void fadump_exclude_reserved_area(unsigned long long start,
+static int fadump_exclude_reserved_area(unsigned long long start,
 					unsigned long long end)
 {
 	unsigned long long ra_start, ra_end;
+	int ret = 0;
 
 	ra_start = fw_dump.reserve_dump_area_start;
 	ra_end = ra_start + fw_dump.reserve_dump_area_size;
 
 	if ((ra_start < end) && (ra_end > start)) {
 		if ((start < ra_start) && (end > ra_end)) {
-			fadump_add_crash_memory(start, ra_start);
-			fadump_add_crash_memory(ra_end, end);
+			ret = fadump_add_crash_memory(start, ra_start);
+			if (ret)
+				return ret;
+
+			ret = fadump_add_crash_memory(ra_end, end);
 		} else if (start < ra_start) {
-			fadump_add_crash_memory(start, ra_start);
+			ret = fadump_add_crash_memory(start, ra_start);
 		} else if (ra_end < end) {
-			fadump_add_crash_memory(ra_end, end);
+			ret = fadump_add_crash_memory(ra_end, end);
 		}
 	} else
-		fadump_add_crash_memory(start, end);
+		ret = fadump_add_crash_memory(start, end);
+
+	return ret;
 }
 
 static int fadump_init_elfcore_header(char *bufp)
@@ -939,13 +1010,22 @@ static int fadump_init_elfcore_header(char *bufp)
  * Traverse through memblock structure and setup crash memory ranges. These
  * ranges will be used create PT_LOAD program headers in elfcore header.
  */
-static void fadump_setup_crash_memory_ranges(void)
+static int fadump_setup_crash_memory_ranges(void)
 {
 	struct memblock_region *reg;
 	unsigned long long start, end;
+	int ret;
 
 	pr_debug("Setup crash memory ranges.\n");
 	crash_mem_ranges = 0;
+
+	/* allocate memory for crash memory ranges for the first time */
+	if (!max_crash_mem_ranges) {
+		ret = allocate_crash_memory_ranges();
+		if (ret)
+			return ret;
+	}
+
 	/*
 	 * add the first memory chunk (RMA_START through boot_memory_size) as
 	 * a separate memory chunk. The reason is, at the time crash firmware
@@ -953,7 +1033,9 @@ static void fadump_setup_crash_memory_ranges(void)
 	 * specified during fadump registration. We need to create a separate
 	 * program header for this chunk with the correct offset.
 	 */
-	fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
+	ret = fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
+	if (ret)
+		return ret;
 
 	for_each_memblock(memory, reg) {
 		start = (unsigned long long)reg->base;
@@ -973,8 +1055,12 @@ static void fadump_setup_crash_memory_ranges(void)
 		}
 
 		/* add this range excluding the reserved dump area. */
-		fadump_exclude_reserved_area(start, end);
+		ret = fadump_exclude_reserved_area(start, end);
+		if (ret)
+			return ret;
 	}
+
+	return 0;
 }
 
 /*
@@ -1097,6 +1183,7 @@ static int register_fadump(void)
 {
 	unsigned long addr;
 	void *vaddr;
+	int ret;
 
 	/*
 	 * If no memory is reserved then we can not register for firmware-
@@ -1105,7 +1192,9 @@ static int register_fadump(void)
 	if (!fw_dump.reserve_dump_area_size)
 		return -ENODEV;
 
-	fadump_setup_crash_memory_ranges();
+	ret = fadump_setup_crash_memory_ranges();
+	if (ret)
+		return ret;
 
 	addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
 	/* Initialize fadump crash info header. */
@@ -1183,6 +1272,7 @@ void fadump_cleanup(void)
 	} else if (fw_dump.dump_registered) {
 		/* Un-register Firmware-assisted dump if it was registered. */
 		fadump_unregister_dump(&fdm);
+		free_crash_memory_ranges();
 	}
 }